Abstract
A progressive retry recovery system based on checkpointing, message logging, rollback, message replaying and message reordering is disclosed. The disclosed progressive retry system minimizes the number of involved processes as well as the total rollback distance. The progressive retry recovery system includes a fault tolerant software library which provides a number of functions which may be invoked by application processes to implement fault tolerance. Fault tolerant functions are provided for allowing an application process to generate a heartbeat message at specified intervals indicating that the application process is still active. In addition, fault tolerance implementation functions are provided for specifying critical memory, for executing checkpoints to store backup copies of critical data, and for restoring critical data during a recovery. In addition, functions are provided which process messages that are sent or received by an application process and maintain logs of the sent and received messages. The progressive retry recovery method consists of a number of retry steps which gradually increase the scope of the rollback when a previous retry step fails.
Original language | English (US) |
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U.S. patent number | 5440726 |
Filing date | 6/22/94 |
State | Published - Aug 8 1995 |